Friday, December 30, 2016

Major Storm

A sprawling storm system stretching from far eastern Russia to interior and northern Alaska brought heavy snow to the Fairbanks area last night and is now producing strong winds (gusting to 50mph at the airport in the past couple of hours).  Here are preliminary snowfall totals from the NWS as of this morning:

Public Information Statement
National Weather Service Fairbanks AK
822 AM AKST Fri Dec 30 2016

...Snowfall Reports...

Location                     Amount    Time/Date       Lat/Lon              

...Middle Tanana Valley...
3 S Fox                      9.4 in    0500 AM 12/30   64.92N/147.62W       
20 NW Fox                    9.0 in    0500 AM 12/30   65.18N/148.07W       
1 NW Fairbanks               8.0 in    1100 PM 12/29   64.85N/147.69W       
2 NW College                 8.0 in    1000 PM 12/29   64.89N/147.88W       
2 N College                  8.0 in    0900 PM 12/29   64.90N/147.82W       
3 SSW Fox                    8.0 in    1000 AM 12/29   64.92N/147.65W       
4 NNW Fairbanks              7.6 in    1000 AM 12/29   64.89N/147.68W       
3 N Fairbanks                5.9 in    0830 PM 12/29   64.88N/147.65W       
Fox                          5.8 in    0845 PM 12/29   64.96N/147.63W       
2 W Two Rivers               5.5 in    1000 PM 12/29   64.87N/147.17W       
Two Rivers                   5.5 in    1000 PM 12/29   64.87N/147.09W       
North Pole                   4.0 in    0800 PM 12/29   64.75N/147.36W       
4 SSW College                12.9 in   0400 AM 12/30   64.82N/147.88W       
3 SW College                 11.8 in   0530 AM 12/30   64.84N/147.90W       
3 SW College                 11.8 in   0200 AM 12/30   64.84N/147.90W       
2 NNW College                11.7 in   0617 AM 12/30   64.89N/147.85W       
12 SW Ester                  11.0 in   0300 AM 12/30   64.74N/148.32W       
3 N Fairbanks                10.4 in   0530 AM 12/30   64.88N/147.65W       
1 E College                  10.0 in   0123 AM 12/30   64.87N/147.79W       

...Lower Koyukuk and Middle Yukon Valleys...
Kaltag                       9.0 in    0600 PM 12/29   64.34N/158.69W       

...Central Interior...
Nenana                       10.0 in   0300 AM 12/30   64.54N/149.09W
 

The surface and 500mb charts show the powerful southwesterly flow that is typical of heavy snow events in Fairbanks.  Here are the maps from 3pm AKST yesterday (click to enlarge):




and from 3am today:



The intensity of the flow into the interior is very pronounced and explains both the abundant moisture (snowfall) and windy conditions.  This afternoon's sounding from Fairbanks airport measured a wind speed of 47mph at 925 mb (~2000 feet above ground), which is the strongest in more than 6 years during the winter season.  The sounding (see below) also shows a remarkably strong lapse rate in the lower troposphere, meaning that the temperature profile is highly favorable for vertical mixing and downward transport of momentum.  It's very rare to see this kind of temperature profile in mid-winter: only one December day in Fairbanks history had a more unstable sounding from the surface to 700mb; that day was December 12, 1972, when 13.9" of snow fell over a 3-day period.



December 2016 is now in 5th place for total snowfall (1930-present) and will probably reach 3rd place by tomorrow.

3 comments:

  1. The NWS models served us well with their forecasts. Now to figure out how to eliminate the "H's" in the Gulf of Alaska/North Pacific that feed the fray.

    Gary

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    Replies
    1. Well put... seasoned forecasters know the importance of the positioning and strength of the H's for all types of wintry weather.

      Sustained winds of 29kt overnight at the airport are the strongest for the time of year since 1970.

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    2. Haven't searched all but gusts close to 50 were reported at Fairbanks Interntional. The wind spun my amateur radio beam antenna 90* in the rotator...a first. The ground is covered with broken tree branches, but whatever snow fell soon departed for parts NE.

      Many locally reported power outages: https://outage.gvea.com

      Gary

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